1. Field of the Invention
The present invention relates to a lens-fitted photographic film unit, wherein a unit body containing a roll of photographic film has a taking lens and an exposure mechanism, and is encased in an outer case which is made of a blanked sheet material. And more particularly, the present invention relates to a lens-fitted photographic film unit whose unit body has at least a curved surface and whose outer case is improved in flexibility in a portion covering the curved surface of the unit body.
2. Background Art
Lens-fitted photographic film units, hereinafter referred to as film units, have been known as a kind of single-use preloaded camera which is affordable for everyone and permits enjoying photography with ease.
In view of the above use, it is desirable to make the film units as compact as possible. To minimize the thickness as well as improve the appearance, a film unit has a front wall that extends behind a taking lens and behind a front wall of a cylindrical film chamber containing a roll of unexposed photographic film. As the film chamber is disposed on the right of the taking lens, a protuberance having a semi-cylindrical shape, corresponding to the front wall of the film chamber, is formed as a grip on the front right of the unit body.
Since the film units must also be inexpensive, the unit body is wrapped with or encased in an outer case having an ornamental pattern printed thereon, in order to make the appearance more attractive at a low cost. The ornamental pattern further serves to indicate the type of the preloaded photographic film, the type of the taking lens, the format of the picture frame, the instructions how to use the film unit, and so forth. Moreover, the outer case prevents the dust from gathering on the unit body or entering inside the unit body. The outer cases are mostly made of cardboard and are formed by folding and sticking a blanked sheet of cardboard into a box.
However, the outer case of the film unit having a grip protruding from the front wall tends to separate from the unit body in the border between the front wall and the grip, because of the difference in thickness between the grip and the remaining portion of the unit body. Such a removal of the outer case will make the film unit insecure to hold. Furthermore, due to resiliency of the cardboard, the folded portions of the outer case tend to unfold, so the outer case tends to bulge or swell.
The bulged outer case cannot sufficiently protect the unit body from the dust, and also spoils the appearance of the film unit. If the outer case swells in the portion covering the grip, it also lowers reliability of grip.